PIP: Obesity is known to affect many aspects of the metabolism of steroid hormones. Both Depo-Provera and Norigest are highly lipid-soluble steroids so that it might be expected that their metabolism would be especially affected in obesity. This study compares rate of uptake and metabolism in these 2 steroids in groups of obese and thin women. Each of 4 groups (each steroid taken by both thin and obese women) of 10 women was injected with either Depo-Provera or Norigest and blood was collected prior to injection and at weekly intervals during the following 12 weeks. There was no significant difference in the serum levels of the contraceptive steroids between the groups. Both follicular and luteal activity returned earlier in women injected with Norigest, but there was no difference between thin and obese women in this area. The authors conclude that the blood concentrations of the steroids do not differ markedly between thin and obese women but this does not rule out the possibility that other more intricate metabolic changes might occur.